Pulp grinder



April 26, 1927.

- J. D. ULLGREN un? GRINDER Filed July 11. 1924 2 Sheets-Sheet .l

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. .1. D. ULLGREN PULP GRINDER 2 Shets-Sheet 2 Filed July 11, 1924 Even/or Patented Apr. 26, 1927.

UNITED STATES PATENT OFFICE.

JOHAN DANIEL ULLGBEN, OF STOCKSUND, SWEDEN, ASSIGNOR 'IO .AKTIEBOLAGET KARLSTADS MEKANISKA. VERKSTAD, OF KARLSTAD, SWEDEN, A SWEDISH COM- PANY.

PULP GRINDER.

Application filed July 11, 1924, Serial No.

The present invention relates to an improvement in pulp grinders and is principally characterized by that the magazine of the grinder is movably connected with the sta tionary frame of the grinder and actuated by springs, weights, or other means, which tend to move the magazine and the wood in the same towards the stone of the grinder, there being also provided in the magazine a pressure cylinder with a piston, or other pressure means, acting between the magazine and the wood in the same to feed the wood through the magazine towards the stone of the grinder. When the pressure on the wood required for feeding the same forward in the magazine is exerted by means of the said piston, or other pressure means, such pressure acting between the movable magazine and the wood bearing against the stone will of course move the magazine away from the stone, until such pressure is balanced by the springs, weights, or the like, which tend to move the magazine towards the stone. The magazine may therefore be moved towards the stone by said springs, weights, or the like, and force the wood against the stone when the pressure means normally feeding the wood forward in the magazine is retracted for the purpose of allowing more wood to be filled into the magazine.

In the accompanying drawings two embodiments of the invention are illustrated by way of example. Fig. 1 shows one construction partly in vertical section, and Fig. 2 shows a portion of a second construction, also partly in vertical section.

Referring to Fig. 1, 1 denotes the stone of the grinder, and 2 is the stationary frame of the grinder surrounding said stone. 3 denotes the wood magazine which is movable in the stationary frame 2 towards and away from the stone in a radial direction. In the embodiment illustrated the magazine 3 is forced towards the stone by springs 4 which are inserted between a flange 5 on the magazine 3 and nuts 6 on bolts 7 secured to the stationary frame 2 and passing through apertures in the flange 5. In the magazine there is provided a pressure means for feeding the wood 8 downwards in the magazine towards the stone 1, said means consisting in the embodiment illustrated of a hydraulic pressure cylinder 9 the pis on 725,332, and in Sweden August 11, 1923.

rod of which is provided with a head 10 which acts on the wood 8. The hydraulic pressure in the cylinder 9 will thus act downwards pressing the head 10 against the Wood S and the wood against the stone 1, and will also act upwards and lift the magazine 3, with the result that the springs 1 become compressed until the pressure exerted by said springs counter-balance the hydraulic pressure in the cylinder 9.

During the grinding the magazine 3 will thus occupy a position raised or retracted from the-stone 1 with the springs 4t compressed, and the wood 8 is fed successively downwards by the head 10. When the piston in the cylinder 9 has reached the end of its stroke it is retracted in the cylinder 9 in order to enable more wood to be filled into the magazine at the top thereof. Meanwhile the magazine 3 shall move downwards towards the stone under the actuation of the springs 1 and bring along the wood which is no longer under pressure from the head 10. For this purpose those walls 11 of the magazine. between which the wood is fed downwards towards the stone, and which in the embodiment illustrated are formed by guide bars 12 secured in the magazine, are given such inclination towards one another that the wood will become pinched between said walls at the said movement of the magazine 3 towards the stone 1 when the counterpressure from the stone will of course tend to push the wood upwards in the magazine which is prevented, however, by the said pinching of the wood. F or the same purpose the said walls 11 may of course be provided with teeth or offsets directed downwards and which provide abutments for the wood against such upward displacement in the magazine. Furthermore, as illustrated in the drawing, dogs or hooks 13 may be pivoted along the walls 11 in such manner that, actuated by their own weight or by springs or the like, they tend to swing in behind the wood in the magazine and thus provide stops for the wood. IV hen the wood is fed downwards in the magazine by the head 10 said hooks will be course be moved'aside by the wood and will afterwards swing in behind the wood.

It will easily be understood by those skilled in the art that in the embodiment illustrated in Fig. 1, where the magazine 3 is til) movable in a vertical direction, the springs 4: may be omitted, and the magazine may be allowed to move in a direction towards the stone under the actuation of its own weight, or additional weights attached to the magazine when required. Other equivalent means for forcing the magazine towards the stone may, of course, also be used. Fig. 2 illustrates an embodiment in which the magazine is forced towards the stone by hy draulic or pneumatic pressure acting on the magazine.

Referring to Fig. 2, 2i denotes the grindng stone, and 22 is he stationary frame of he grinder in which the magazine 23 is guided and movable towards and away from the stone. The end of said magazine remote from the stone is shaped as a piston 2 .2 which slides in a cylinder 25 integral with or secured to the frame and in which a pneumatic or hydraulic pressure of the required height is maintained for forcing the magazine and the wood in the same towards the stone.

The logs 25 drop or roll from a hopper 27 through an opening 28 in the upper wall of the magazine 23 into said magazine in frontof a presshead 29 which is secured to the rod 30 of a piston 31 movable in a cylinder 32 in the outer end of the magazine 23. Said piston 31 is actuated by pneumatic or hydraulic pressure, and when it is allowed to move towards the stone it pushes the logs forward in the magazine towards the stone. The pressure in the cylinder 3'2 acting between the magazine and the piston 31 it will be understood that said pressure only acts to move the wood forwards in the magazine and is not transferred through the logs to the stone, the pressure of the logs on the stone being determined by the pressure in the cylinder and consequently the pressure on the stone may easily be maintained absolutely constant, as it is quite in dependent of the force required for overcoming the friction between the logs and. the magazine.

When the press-head 29 actuated by the piston 3L has moved the wood forwards so far in the magazine that the piston 31 is at the end of its inward stroke, the pressure on the piston 31 is reversed to retract the piston and the press-head 29 to the position shown in the drawing. More logs fall now into the magazine from the hopper T he logs already in the magazine are held in place by the inclined walls of the magazine pinching the logs and preventing outward movement of the same, and also by dogs 3% pivoted at 35 and actuated by weights 36 and adapted to move in behind the logs, as shown in Fig. 2. Further dogs 87 actuated by springs may be provided, such dogs being adapted to engage the logs in similar manner. When the press-head 29 again moves forward to move the logs towards the stone said dogs 3% and 37 are moved aside by the logs.

Vi hen the logs drop into the magazine from the hopper 27 it may of course easily happen that a portion of a log lies above the edge of the opening 28, with the result that when the press-head 29 moves forward said log would be pinched between the presshead and the edge .38 of the opening 28, and thus stop the press-head and the piston 31 with the result that the forward feeding of the logs in the magazine 23 would cease. In order to avoid this the said edge 38 is provided with a knife or cutting edge 39 which will act to cut oil the portion of the log which projects outside the magazine, so that the remaining portion of the log may be pushed forward below said knife 59 and e lge 38 in the magazine.

The press-head 29 may also suitably be provided with a knife or cutting edge do which is adapted to cooperate with the knife 39 for cutting oil splints or chips which may join the cut-off portion of a log to the portion within the magazine. Er plate or shield i1 is suitably secured to the presshead :29 and serves to prevent the logs in the hopper 27 from dropping behind the press-head 29 when said press-head moves forward in the magazine.

I claim:

1. in a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine, means in said magazine for feeding wood through the same towards said stone, and means actuating said magazine in a direction towards said stone for feeding wood to the latter during the interruption of said feeding means.

2. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine, means in said mag azine for feeding wood through the same towards said stone, means in said magazine acting to prevent movement of the wood in the same in a direction away from said stone, and means actuating said magazine in a direction towards said stone for feeding wood to the latter during the interruption of said feeding means.

3. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a Wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feed ing wood through the same towards said stone, said magazine having walls inclined towards each other and adapted to pinch the wood and prevent movement of the same in the magazine in a. direction away from said stone, and means actuating said magazine in a direction towards said stone,

4. In a pulp grinder the combination of a frame, a grinding stone rotatable in said ill) frame, a wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feeding wood through the same towards said stone, dogs attached to said magazine and adapted to move in behind the wood in the same so as to prevent movement of the wood in the magazine in a direction away from said stone, and means actuating said magazine in a direction towards said stone.

5. In a pulp grinder the con'ibinat-ion of a frame, a grinding stone rotatable in said frai'ne, a wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feeding wood through the same towards said stone, said magazine having walls inclined towards each other and adapted to pinch the wood so as to prevent the same from movement in the magazine in a direction away from said stone, dogs attached to said magazine and adapted to move in behind the wood in the same so as to prevent movement of the wood in the magazine in a direction away from said stone, and means actuating said magazine in a direction towards said stone.

6. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feeding wood through the same towards said stone, and a pressure cylinder urging said magazine in a direction towards said stone.

7. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine movable in said frame in a direction towards and away from said stone, a pressure cylinder in said magazine, a piston in said cylinder, carrying a press-head adapted to act upon the wood in said magazine to feed the same towards said stone, and means urging said magazine in a direction towards said stone.

8. In a pulp grinder, the combination of a rotary grinding stone, a wood magazine, means for feeding wood through said magazine towards said stone, said magazine being provided with a filling opening, and a knife provided at one edge of said opening.

9. In a pulp grinder, the combination of a rotary grinding stone, a wood magazine, means for feeding wood through said magazine towards said stone, said magazine being provided with a filling opening, a knife provided at one edge of said opening, and a knife carried by said feeding means and adapted to cooperate with said firstmentioned knife.

10. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feeding wood through the same towards said stone, said magazine being provided with a filling opening, cutting means at one edge of said opening, and means actuating said magazine in a direction towards said stone.

11. In a pulp grinder the combination of a frame, a grinding stone rotatable in said frame, a wood magazine movable in said frame in a direction towards and away from said stone, means in said magazine for feeding wood through the same towards said stone, said magazine being provided with a filling opening, cutting means at one edge of said opening, cutting means carried by said feeding meansand adapted to cooperate with said first-mentioned cutting means, and means actuating said magazine in a direction towards said stone.

12. In a pulp grinder, the combination of a frame, a grinding stone, a wood magazine mounted for movement in said frame, means tending to move said magazine toward said stone, and means for feeding wood through said magazine to said stone, said feeding means being adapted to retract said maga zine against the action of said first named means during the normal operation of said feeding means, said first named means serving to move said magazine toward said stone to feed wood thereto upon the interruption of said feeding means.

13. In a pulp grinder, the combination of a frame, a grinding stone, a wood magazine slidably mounted in said frame, means secured to said magazine for feeding wood therethrough to said stone, said magazine being movable in a direction away from said stone by the reaction of said feeding means upon the operation of the latter, and means for moving said magazine towards said stone to feed wood thereto upon the interruption of said feeding means.

JOHAN DANIEL ULLGREN. 

